content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  
  package io.reactivex.flowable.internal.operators;
  
  import java.util.concurrent.atomic.*;
  
  import org.reactivestreams.*;
  
  import hu.akarnokd.reactivestreams.extensions.RelaxedSubscriber;
  import io.reactivex.common.RxJavaCommonPlugins;
  import io.reactivex.common.exceptions.Exceptions;
  import io.reactivex.flowable.Flowable;
  import io.reactivex.flowable.internal.subscriptions.*;
  
  public final class FlowableAmb<T> extends Flowable<T> {
      final Publisher<? extends T>[] sources;
      final Iterable<? extends Publisher<? extends T>> sourcesIterable;
  
      public FlowableAmb(Publisher<? extends T>[] sources, Iterable<? extends Publisher<? extends T>> sourcesIterable) {
          this.sources = sources;
          this.sourcesIterable = sourcesIterable;
      }
  
      @Override
      @SuppressWarnings("unchecked")
      public void subscribeActual(Subscriber<? super T> s) {
          Publisher<? extends T>[] sources = this.sources;
          int count = 0;
          if (sources == null) {
              sources = new Publisher[8];
              try {
                  for (Publisher<? extends T> p : sourcesIterable) {
                      if (p == null) {
                          EmptySubscription.error(new NullPointerException("One of the sources is null"), s);
                          return;
                      }
                      if (count == sources.length) {
                          Publisher<? extends T>[] b = new Publisher[count + (count >> 2)];
                          System.arraycopy(sources, 0, b, 0, count);
                          sources = b;
                      }
                      sources[count++] = p;
                  }
              } catch (Throwable e) {
                  Exceptions.throwIfFatal(e);
                  EmptySubscription.error(e, s);
                  return;
              }
          } else {
              count = sources.length;
          }
  
          if (count == 0) {
              EmptySubscription.complete(s);
              return;
          } else
          if (count == 1) {
              sources[0].subscribe(s);
              return;
          }
  
          AmbCoordinator<T> ac = new AmbCoordinator<T>(s, count);
          ac.subscribe(sources);
      }
  
      static final class AmbCoordinator<T> implements Subscription {
          final Subscriber<? super T> actual;
          final AmbInnerSubscriber<T>[] subscribers;
  
          final AtomicInteger winner = new AtomicInteger();
  
          @SuppressWarnings("unchecked")
          AmbCoordinator(Subscriber<? super T> actual, int count) {
              this.actual = actual;
              this.subscribers = new AmbInnerSubscriber[count];
          }
  
          public void subscribe(Publisher<? extends T>[] sources) {
              AmbInnerSubscriber<T>[] as = subscribers;
              int len = as.length;
              for (int i = 0; i < len; i++) {
                  as[i] = new AmbInnerSubscriber<T>(this, i + 1, actual);
              }
              winner.lazySet(0); // release the contents of 'as'
              actual.onSubscribe(this);
  
              for (int i = 0; i < len; i++) {
                  if (winner.get() != 0) {
                      return;
                  }
  
                  sources[i].subscribe(as[i]);
              }
          }
  
          @Override
          public void request(long n) {
              if (SubscriptionHelper.validate(n)) {
                  int w = winner.get();
                  if (w > 0) {
                      subscribers[w - 1].request(n);
                  } else
                  if (w == 0) {
                      for (AmbInnerSubscriber<T> a : subscribers) {
                          a.request(n);
                      }
                  }
              }
          }
  
          public boolean win(int index) {
              int w = winner.get();
              if (w == 0) {
                  if (winner.compareAndSet(0, index)) {
                      AmbInnerSubscriber<T>[] a = subscribers;
                      int n = a.length;
                      for (int i = 0; i < n; i++) {
                          if (i + 1 != index) {
                              a[i].cancel();
                          }
                      }
                      return true;
                  }
              }
              return false;
          }
  
          @Override
          public void cancel() {
              if (winner.get() != -1) {
                  winner.lazySet(-1);
  
                  for (AmbInnerSubscriber<T> a : subscribers) {
                      a.cancel();
                  }
              }
          }
      }
  
      static final class AmbInnerSubscriber<T> extends AtomicReference<Subscription> implements RelaxedSubscriber<T>, Subscription {
  
          private static final long serialVersionUID = -1185974347409665484L;
          final AmbCoordinator<T> parent;
          final int index;
          final Subscriber<? super T> actual;
  
          boolean won;
  
          final AtomicLong missedRequested = new AtomicLong();
  
          AmbInnerSubscriber(AmbCoordinator<T> parent, int index, Subscriber<? super T> actual) {
              this.parent = parent;
              this.index = index;
              this.actual = actual;
          }
  
          @Override
          public void onSubscribe(Subscription s) {
              SubscriptionHelper.deferredSetOnce(this, missedRequested, s);
          }
  
          @Override
          public void request(long n) {
              SubscriptionHelper.deferredRequest(this, missedRequested, n);
          }
  
          @Override
          public void onNext(T t) {
              if (won) {
                  actual.onNext(t);
              } else {
                  if (parent.win(index)) {
                      won = true;
                      actual.onNext(t);
                  } else {
                      get().cancel();
                  }
              }
          }
  
          @Override
          public void onError(Throwable t) {
              if (won) {
                  actual.onError(t);
              } else {
                  if (parent.win(index)) {
                      won = true;
                      actual.onError(t);
                  } else {
                      get().cancel();
                      RxJavaCommonPlugins.onError(t);
                  }
              }
          }
  
          @Override
          public void onComplete() {
              if (won) {
                  actual.onComplete();
              } else {
                  if (parent.win(index)) {
                      won = true;
                      actual.onComplete();
                  } else {
                      get().cancel();
                  }
              }
          }
  
          @Override
          public void cancel() {
              SubscriptionHelper.cancel(this);
          }
  
      }
  }
  